The life cycle and ecology of the olive fly (Bactorcera oleae Gmelin) is linked to the seasonal development of olive trees and to local climate condition. Despite the fact that olive fruit fly activity depend on weather condition and it’s the Mediterranean’s the most important pest of olives, the effects of climatic condition on population dynamics of the olive fly is relatively poorly known. Because of this lack of information, annual monitoring of the population dynamics of the olive fly was conducted in slovene Istria by using yellow plastic strip covered with non-drying adhesive and pheromone trap in 2005, 2006, 2007, 2008 and 2009, and factors including temperature, rainfall and relative humidity with respects to the population fluctuation were analyzed systematically. The results showed that, meteorological conditions have significant effect on population abundance of olive fly in slovene Istria, despit the fact that climatic conditions had little direct influence on population dynamic of adult males of olive fly.
COBISS.SI-ID: 2085843
Slovenia witnesses lack of experience in olive irrigation. Olives are often irrigated by employing the principle of “crisis irrigation”, which means that water is added in unmonitored amounts in terms of time and quantity. Owing to increased occurrence of agricultural droughts and extremely limited water resources in Slovene Istria, the irrigation principle has to be adapted to water resources. In order to determine the optimum irrigation application and to study the impact of “deficient irrigation” on olive tree growth and crop yield, we have carried out experimental olive irrigation in the area of Slovene Istria. The research results show that “optimum irrigation” (100% ETp) increases the crop yield by 47%, while “deficient irrigation” (33 and 66% ETp) can increase it by 22-26%. Even if the latter technique means lower crop yields, water stress has a positive impact on earlier fruit maturation and on tree growth and development, and increases oil accumulation in fruits. According to a rough estimate based on our research results, it would be sensible to introduce “deficit irrigation” in olive growing in Slovene Istria since even a lower water application (than necessary in the optimum case) increases plant productivity, thus ensuring better crop yields and sustainable use of water resources.
COBISS.SI-ID: 2175699
The article describes the development of an identification method of carbohydrates as the primary products of photosynthesis. First research into the Slovene types of olive oil was conducted more than twenty years ago. What makes the study of the presence of carbohydrates in different olive parts interesting is the fact that carbohydrates are the precursors of many biological molecules, including lipids. They are also a component of oil biophenols, and are associated with some important phenomena, such as alternate bearing in olive and its great drought tolerance. We have tested different sugar extraction methods, with the most appropriate having been proved to be the extraction of sugars and biophenols from fruits using water. In the next step, biophenols were extracted from water solution by using ethyl acetate. Water was also used in order to extract sugars from leaves, with the extract being then centrifuged and filtered. The sugars in extracts from olive fruits and leaves were identified through high resolution liquid cromotography. The method developed allows for further research into olives, e.g. the characterization of varieties thriving in Slovene Istria and the investigation of correlations between sugar content and different climate conditions (e.g. drought).
COBISS.SI-ID: 2176979
The paper describes the monitoring of olive fly (Bactrocera oleae Gmelin) which was performed across the Slovenian Istria. We carried out the monitoring weekly in 2010 and 2011 at 31 locations in the coastal and hinterland part of the Slovenian Istria with pheromone traps that attract sexually mature males. At the time of endocarp lignification through to the harvesting of fruits, we were also determining the development stage of the pest on the base of randomly picked hundred fruits which were examined under a stereo magnifier. All the time through the experiment, we recorded meteorological data (temperature, precipitation, relative humidity and wetness of leaves) in order to determine the impact of weather on the population of the olive fly. On the basis of the processed collected data we concluded that the population of the olive fly was higher in 2011 in comparison to 2010. Consequently, the damage caused by the olive fruit fly was much higher in 2011. We concluded that the increased occurrence of olive fly in 2011 was due to favorable winter weather conditions that allowed numerous flies to spend the winter.
COBISS.SI-ID: 2175443